<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>绝对定位</title>
    <style>
        #outer{
            width: 600px;
            height: 100px;
            background-color: darkseagreen;
        }
        #inner1{
            width: 400px;
            height: 30px;
            background-color: red;
            position: absolute;
            left: 10px;
            top: 10px;
        }
        #inner2{
            width: 400px;
            height: 30px;
            background-color: blue;

        }
    </style>
</head>
<body>
    <div id="outer">
        <div id="inner1"></div>
        <div id="inner2"></div>
    </div>
</body>
</html>